// Filename JulianDateException.java.
 // Providing specific exception for JulianDate class
 //
 // Written for JFL book Chapter 9 see text.
//  From the JFL textbook, typed in by X. Meng 
 
package JulianDates;

public class JulianDateException extends RuntimeException { 
 
public static final int NULL_DATE         = 0; 
public static final int DATE_INPUT_ERROR  = 1;
public static final int ARITHMETIC_ERROR  = 2; 
public static final int DATE_CONSTRUCTION_ERROR  = 3; 

private int theReason; 
    
    public JulianDateException( int reason) {
       super();
       theReason = reason;
    } // End principal constructor
    

    public int obtainReason(){ 
       return theReason;    
    } // End obtainReason.
    
    
    public String toString(){ 
     String toReturn;
     
        switch ( theReason) {  
        case NULL_DATE: 
           toReturn = new String( "JulianDate exception : Empty date.");
           break;
        case DATE_INPUT_ERROR: 
           toReturn = new String( "JulianDate exception : Date input incorrect.");
           break;          
        case ARITHMETIC_ERROR: 
           toReturn = new String( "JulianDate exception : Arithmetic error.");
           break;          
        case DATE_CONSTRUCTION_ERROR: 
           toReturn = new String( "JulianDate exception : Constructor error.");
           break;          
        default: 
           toReturn = new String( "JulianDate exception : Unknown reason.");
        } // End switch. 
        return toReturn;    
    } // End toString.

} // End JulianDateException.